Thermally-bonded (polyester) fiberfill batts (or battings) are well known and have gained large scale commercial use, particularly in Europe. Binder fibers can be blended intimately into the fiberfill to achieve true "through-bonding" of fiberfill batts, and thus achieve better durability versus resin-bonding, which was the conventional method, and can also provide reduced flammability versus resin-bonding. Such binder fiber blends are used on a large scale in furnishings, mattresses and similar end-uses where strong support is desired. However, they are seldom used as the only filling material in these end-uses, particularly in furnishing seat cushions, where the common practice is to use the fiberfill batts as a "rapping" for a foam core. It is believed that the main reason is probably that, to obtain the desired resilience and performance in 100% fiberfill cushions, it would be necessary to provide such relatively high density as has hitherto been considered too costly and difficult with the present techniques, and as might not provide desirable performance aesthetically. In a conventional fiberfill batt, the fibers are arranged in parallel layers which are bonded together. In such a layered structure, any pressure applied during use as a cushion is essentially perpendicular to the direction of the fibers and I believe that may be at least partly why such a high density must be reached to achieve the desired resilience and durability using conventional layering and bonding techniques.